The invention relates generally to the field of telephone interconnected paging systems, and more particularly to improved systems for relaying phoned messages to designated paging receivers.
Radio paging systems are gaining acceptance in a variety of areas. For example, in hospitals a paging system is useful for contacting doctors anywhere on the premises without broadcasting the page over loudspeakers. A small paging receiver, such as the "Pageboy" (Trademark) unit marketed by Motorola, Inc., is worn or carried by each individual to be paged. The paging receiver emits an audible alerting signal in response to a corresponding radio signal transmitted from a central station.
Radio paging systems are divided into two basic types: those which require an operator and those which operate automatically. In the manned systems, an outside caller phones the operator who takes the caller's message, looks up the paging number of the person for whom the message is intended, and then contacts the designated paging receiver with the transmitter. After the receiver emits an audible tone, the individual must call the operator to learn the reason he is being paged. Alternatively, the operator may repeat the caller's message through the transmitter if the paging receiver is adapted for audio reception.
In prior automatic paging systems, the central station is equipped with TOUCH TONE logic circuitry and a paging encoder which causes the paging signal to be transmitted automatically to the receiver in response to a supplementary multidigit paging number keyed to the caller. This system is referred to as telephone interconnected dialing or "end-to-end" signalling. In some prior art automatic systems, the central station transmits the caller's voice message, as it is given, directly to the receiver after contact is established.
These prior art systems all lack the flexibility required to handle automatically and efficiently a number of simultaneously incoming calls for different paging receivers. Moreover, automatic telephone interconnected paging systems in the past have required TOUCH TONE operation by the caller. The majority of personal phones now in use have the traditional rotary dial. Although during dialing there is a DC (direct current) connection between the caller's phone and the telephone company exchange, the subsequent connection to the called phone (herein the central station) is by inductive circuits which do not permit normal transmission of DC pulses from the rotary dial.